Functional bowel disorders involve abnormal motility and secretion within organs of the gastrointestinal (GI) tract, and are characterized by abdominal discomfort/pain. The criteria for these disorders are summarized by gastroenterologists in the ‘Rome II criteria’. Based on these criteria the disorders are common and include, but are not limited to, functional dyspepsia, irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD) and non-erosive reflux disease (NERD), and chronic constipation (including colonic inertia, idiopathic pseudoobstruction). GERD is extremely prevalent, is usually associated with non-cardiac chest pain and may be treated with acid-suppressing agents and prokinetic agents. IBS is characterized by the presence of reoccurring constipation and/or diarrhea, which can be associated with gaseous distention/bloating and abdominal discomfort/pain (Thompson, W. G. and Heaton, K. W. Gastroenterology 1980, 79, 283-288). The onset of the pain of IBS is associated with a change in the frequency and/or form of stool and can be relieved by defecation. IBS is an extremely prevalent condition that occurs to varying severity in 10-15% of the population (Saito, Y. A.; Schoenfeld, P.; and Locke, G. R. Am. J. Gastroenterol. 2002, 97, 1910-1915). The pain may be treated with smooth muscle relaxants and antidepressants (Jackson, J. L.; O'Malley, P. G.; Tomkins, G.; Balden, E.; Santoro, J.; and Kroenke, K.; Am. J. Med. 2000, 108, 65-72; Jailwala, J.; Imperiale, T. F.; and Kroenke, K.; Ann. Intern. Med. 2000, 133:136-147; Akehurst, R. and Kaltenthaler, E. Gut 2001, 48, 272-282; Poynard, T.; Regimbeau, C.; and Benhamou, Y.; Aliment Pharmacol. Ther. 2001, 15, 355-361). Severe diarrhea predominant IBS is treated by alosetron, whereas constipation predominant IBS is treated by tegaserod. Functional dyspepsia is a disorder of the upper GI tract with symptoms exacerbated by a meal and associated with early satiety, nausea and vomiting. Although its etiology is unknown, prokinetic agents may relieve the symptoms of IBS. In some patients there is overlap in symptoms between GERD/NERD, functional dyspepsia and IBS. Treatments for functional bowel disorders, such as IBS, have low efficacy and are associated with adverse effects. For example, alosetron is approved by the FDA on a risk management program because it is associated with an increase in a serious adverse event, ischemic colitis. No treatments effectively alleviate pain in functional bowel disorders.
In addition to functional disorders, inflammatory bowel diseases (IBD) are common and include ulcerative colitis (UC) and Crohn's disease (CD). Although there may be a genetic component to CD, the etiology of both CD and UC is unknown.
UC is a diffuse mucosal disease of the colon, characterized by inflammation and ulceration, which is associated with diarrhea and abdominal cramping. The mucosal inflammation progresses from the rectal area to eventually extend through the large bowel. CD is a transmural inflammation that most frequently involves the distal small bowel and colon. The inflammation can result in ulcers of varying involvement and in severe cases result in transmural scarring and chronic inflammation. Both infectious and dysregulated immune functions may contribute to disease onset. Therapies for IBD include corticosteroids, immunosuppressives (azathioprine, mercaptopurine, and methotrexate) and aminosalicylates (5-ASA). These therapies involve suppression of the immune system by mimicking corticoids, or unknown mechanisms of action. Oral corticosteroid use is associated with serious adverse effects, whereas immunosuppressives and aminosalicylates are only moderately effective. Infliximab (a chimeric monoclonal anti-tumor necrosis factor antibody) is effective in CD, however, its use is associated with the presence of antibodies, which reduce its efficacy. There are no treatments that target the motility and secretory abnormalities or painful sensation that are associated with gut inflammation.
The cysteine rich proteins known as Prokineticin 1 (PK1) and Prokineticin 2 (PK2), as well as variants, fragments and molecules having PK activity, have been identified. These have been shown to contract gastrointestinal smooth muscle (Li, M.; Bullock, C. M.; Knauer, D. J.; Ehlert, F. J.; and Zhou, Q. Y., Mol. Pharmacol. 2001, 59, 692-698), and suppress feeding (Negri, L.; Lattanzi, R.; Giannini, E.; De Felice, M.; Colucci, A. and Melchiorri, P. Brit. J. Pharmacol. 2004, 142, 181-191). PK1 and PK2 act on both PK1 and PK2 receptors, and limited structural changes of C-terminal cysteine-rich regions of these related PKs are tolerated. For example, chimeric PKs, where the cysteine-rich domains of PK 1 and PK 2 were exchanged between the two; and a splice variant of PK2 that included a 21 residue insertion in its C-terminal domain retained activity (Bullock, C M; Li J. D.; Zhou, Q. Y.; Mol. Pharmacol. 2004, 65(3), 582-8). A PK variant binds to receptors of primary sensory neurons, and results in an intense sensitization of peripheral nociceptors to thermal and mechanical stimuli (Mollay, C.; Weschelberger, C.; Mignogna, G.; Negri, L.; Melchiorri, P.; Barra, D.; Kreil, G.; Eur. J. Pharmacol. 1999, 374, 189-196; Negri, L.; Lattanzi, R.; Giannini, E.; Metere, A.; Colucci, M.; Barra, D.; Kreil, G.; Melchiorri, P.; Brit. J. Pharmacol. 2002, 137(8), 1147-54).
Patent application PCT/US2004/087054 A2 provides methods of modulating gastric acid or pepsinogen secretion by administering an amount of a prokineticin receptor antagonist effective to alter one or more indicia of gastric acid secretion.
PK1 induces proliferation, migration and fenestration in capillary endothelial cells derived from endocrine glands. The expression of PK mRNA is restricted to the steroidogenic glands, ovary, testis, adrenal and placenta (LeCouter, J.; Kowalski, J.; Foster, J.; Hass, P., Zhang, Z.; Dillard-Telm, L., Frantz, G., Rangell, L.; DeGuzman, L.; Keller, G. A.; Peale, F.; Gurney, A.; Hillan, K. J.; Ferrara, N. Nature 2001, 412 (6850), 877-84). In 2002 the identification of the PK1 receptor provided a novel molecular basis for the regulation of angiogenesis in endocrine glands (Masuda, Y.; Takatsu, Y.; Terao, Y.; Kumano, S.; Ishibashi, Y.; Suenaga, M.; Abe, M.; Fukusumi, S.; Watanabe, T.; Shintani, Y.; Yamada, T.; Hinuma, S.; Inatomi, N.; Ohtaki, T.; Onda, H.; Fujino, M.; Biochem. Biophys. Res. Commun. 2002, 293(1), 396-402; LeCouter, J.; Lin, R.; Ferrara, N.; Cold Spring Harb Symp Quant Biol. 2002, 67, 217-21). For example, adenoviral delivery of PK1 to the mouse testis results in a potent angiogenic response (LeCouter, J.; Lin, R.; Tejada, M.; Frantz, G.; Peale, F.; Hillan, K. J.; Ferrara, N. Proc. Natl. Acad. Sci. USA. 2003, 100, 2685-90). Recently, it was shown that PK1 mRNA is not normally expressed in colorectal normal mucosa but is detected in colorectal cancer cells (Goi, T.; Fujioka, M.; Satoh, Y.; Tabata, S.; Koneri, K.; Nagano, H.; Hirono, Y.; Katayama, K.; Hirose, K. and Yamaguchi., Cancer Res. 2004, 64, 1906-1910).
Prokineticin 1 receptor antagonists are useful in the treatment and prevention of various mammalian disease states, for example, visceral pain that is associated with IBS and IBD. Additionally, PK1 receptor antagonists are useful for the treatment of GERD or other forms of secretory diarrhea. Additionally, PK1 receptor antagonists are useful in treating cancer-specific angiogenesis factor in the large intestine and reproductive organs.
It is an object of the present invention to provide prokineticin 1 receptor antagonists. It is also an object of the invention to provide a method of treating or ameliorating a condition mediated by prokineticin 1 receptor. And, it is an object of the invention to provide a useful pharmaceutical composition comprising a compound of the present invention useful as a prokineticin 1 receptor antagonist.